The M2M (Machine-to-Machine, machine-to-machine) communications technology can implement information transmission, collaboration, and processing between machines, between a machine and a person, and between a machine and another device, by using existing network hardware facilities. In addition, the technology is widely applied to application scenarios such as logistics management, electricity meter reading, and health supervision, thereby enhancing system and personnel working efficiency and reducing manpower costs.
In practical application, generally, an MTC (Machine Type Communications, machine type communications) device needs to be triggered to enable application of the M2M technology in a 3GPP system, and a specific triggering process needs to be performed by using an interface such as T4 and T5. However, if network congestion or overload occurs during the process of triggering the device by using the interface, a network element device such as an SGSN/MME (Serving GPRS Support Node/Mobility Management Entity, Serving GPRS Support Node/Mobility Management Entity) may not effectively send a trigger message to the MTC device.
In order to resolve a triggering overload problem, the prior art provides a triggering overload control solution:
When a network is congested or overloaded, a UE (User Equipment, user equipment), which serves as a triggered end, receives feedback information that includes a back-off timer (back-off timer), and the UE does not send request signaling before the back-off timer times out. In addition, a machine type communications interworking device MTC-IWF, which serves as a triggering end, also receives a message (for example, a transmission result message, a device trigger result message, or a message that is the same as the feedback information received by the UE) that carries a trigger-suppression timer, and the MTC-IWF does not re-send a trigger request before the trigger-suppression timer times out.
However, in many cases, the trigger message has a validity time for triggering, and the trigger message becomes invalid when the validity time expires. For example, the SGSN/MME sends the message that carries the trigger-suppression timer to the MTC-IWF. However, duration of the trigger-suppression timer may be longer than the validity time of the trigger message. When the timer times out, the trigger message has become invalid, so that a trigger message needs to be re-transmitted. This increases information load of a network and further reduces operating efficiency of the network when the network is already congested or overloaded. In addition, transmission of the invalid trigger message is equivalent to adding junk information to the network, which increases the information load of the network that is already congested or overloaded, and further reduces the operating efficiency of the network.